Move the laserspots to light all the lasercells. The laserbeams can not go through the walls. There are objects which are moveable, they are marked with arrows in the middle. Not all the laserspots are moveable. Some laserspots are connected to each other, so if you move the first one, the other one will also move into some other direction. There are also anti-lasercells, which are lit default, so no need to go through these by the laserbeams.